Insecticide



' terlals for destroying Patented July 28, 1942 Lloyd E. Smith, Washington, D. Secretary'of Agriculture of Henry A. Wallace,

0., assignor. to'

the United States of America, and his successors in oiiice No Drawing. Application May 7, 1938,

v Serial No. 206,589

2 Claims. (01. 167-33) (Granted This application is made under the act of March 3", 1883, as amended by the act of-April 30, 1928, and the invention herein described and claimed, if patented, may be manufactured and used by or for the Government of the United States of America. for governmental purposes without the payment to me ofany royalty thereon. V

My'invention relates toimprovements in ma- I n or checking the growth or multiplication of living organisms whether plant or animal, which are economically injurious to man.

- An object or the terial' suitable for use as an insecticide.

Another object of the invention is to provide a material which is relatively non-toxic to man which can be used in place of lead arsenate and other arsenicals for destroying insects without tables.

1 have found that the class or organic compounds known as xanthones and derivatives thereof are efiective in killing many species of insects whether applied externally or internally; that these organic compounds maybe sprayed or dusted upon delicate vegetation without iniurinzit: that'these materials are even morev efliective than lead arsenate and other commonly used insecticides and that they are relatively non-toxic to warm-blooded formulaunder .the act of March amended April 30, 1928; 370 0. G.

invention is to provide a ma- 7 and domestic animals when taken by mouth and leaving a harmful residue on fruits and vegei gave; a 98% kill or- I animals. This class of compounds may be represented by the general powder by either dry as a dust or wet as a spray.

in refined mineral oils,

claim for LettersPatent is: 1. An insecticide in which R and R forming asix membered ring. 7

Some of the hydrogen atoms normally attached to R and R"may be substituted or re-' placed by alkyl, clei, or halogen, or aryloxy groups.-

These products may nitrmamino, hydroxy,

be reduced to impalpable The products being soluble may he applied 'as a component sionspray. it is desirable to incorporate an ting agent such as one of the so-called sulphonated oils. These products may also be applied by dissolving them in acetone and pouring the acetone into water whereupona precipitate is formed. This'may or an oil emulbe applied directly to plants or may be combined with a suitablewetting agent and then sprayed;

As an example of the toxicity of this compounds it was I d that- (1) When used as a micrograms per square centimeter xa'nthone class or 48 hours..- i

'(2) when tested against concentration of one part in ter' the kill was 83%.

Having thus described my some .parts or wainvention containing as its essential sc tive ingredient one oi the class 01 eompmmds known as'xanthones. I

2. An-insecticide containing tive ingredientxanthone.

v are benzene nuclei in each or 'I which 2 adjacent carbon atoms take part in cycloalkyl, aryl, heterocyclic nualkoxy grinding and applied to vegetation When applied as a sprayin water eiiective wet-' line colloidal I dust at a concentration or the southern army worm in.

mosquito larvae at-a whatI asitsjessentialac- 

